Antigenic variation is an immune-evasive, defensive strategy commonly exploited by many viruses. Antigenically variable viruses (AVV) are responsible for many human as well as veterinary diseases with high morbidity/mortality and significant economic losses worldwide. Viruses such as HIV-1, influenza virus and PRRSV (Porcine Reproductive and Respiratory Syndrome Virus) are notorious examples and they epitomize the next level of scientific challenge that mankind faces in a fight against infectious diseases. Considering the enormity of the scientific challenges of antigenic variation, we believe more cross-disciplinary efforts mustbe made to share new advances in various scientific disciplines, exchange novel concepts, and to foster new collaborations between not only those who work on same viruses, but also among investigators who work on different viruses or different disciplines. In June 2014, we hosted the first Symposium on Vaccines Against Antigenically Variable Viruses (VAAVV). The symposium was well attended, which indicated (1) the uniqueness of the symposium, (2) scientific importance of the topic, and (3) significant need for the symposium to move the field forward. To continue the momentum, we are proposing to hold two additional symposia in 2015 and 2016. The major purpose of holding the symposia dedicated to developing VAAVV is to establish a strong network of investigators for conducting highly collaborative, integrative, and interdisciplinary research. This will establish the scientific foundation to develop novel strategis and make strides toward a long-term goal of producing efficacious and cost-effective vaccines against these viruses. We believe our symposium is unique in that it focuses primarily on the topic of antigenic variation, rather than a specific virus. To our knowledge, there are no comparable meetings that bring together investigators who work on different viruses focusing on this important topic. Considering the importance of interdisciplinary collaborations, the symposium will be proactive in facilitating interactions among participants by providing collaboration corners with dedicated time and spaces for attendees to have opportunities to interact directly with speakers. We will also arrange scientific speed dating among attendees to facilitate interactions and to foster collaborative research. In this Symposium, participants wil share, discuss and debate many problems associated with developing effective VAAVV, focusing especially on HIV-1, influenza virus and PRRSV. Many topics will be discussed including current understanding immune correlates of protection, new insights from computational-, structuraland systems-biology for rational immunogen design, and novel strategies for enhancing potency and breadth of immune responses. The specific Aim of the proposal is: To provide an effective venue that would allow sharing of state-of-the-art knowledge and exchange of innovative ideas that could facilitate interdisciplinary research and foster collaboration in order to overcome the problem of antigenic variation in vaccine development.